In 3GPP LTE standardization process, in release 10, TDD carrier aggregation can only support using the same frame configuration of TDD uplink and downlink between different component carriers. While since release 10 evolves to release 11, TDD carrier aggregation between different frequency bands has been able to support using different frame configurations of TDD uplink and downlink between different component carriers. For A/N (ACK/NACK) bit mapping and the resource allocation used for PUCCH format 3, the standardization has reached some agreement. A UE can be configured to have PUCCH format 3 or PUCCH format 1b, and have the channel selection used for HARQ-ACK transmission.
In RAN1#68bis meeting, in the case of self-scheduling (i.e. the scheduling of downlink subframe data of a secondary cell is transmitted by the cell), the industry agrees that: the PDSCH HARQ in the secondary cell will refer to the TDD reference uplink and downlink frame configuration. As shown in the following table 1:
TABLE 1reference frameuplink and downlink frame configurationconfiguration used forof the secondary cell SIB1PDSCH HARQ0123456uplink and00123456downlink11124451frame22225552configuration33453453of the44454454primary cell55555555SIB166123456
The table shows that when uplink and downlink frame configurations of a primary cell and a secondary cell are certain configurations respectively, which reference frame configuration it is, on which the implementation of HARQ feedback is based. E.g. when the frame configuration of a primary cell is the type 2, and the frame configuration of a secondary cell is the type 3, the reference frame configuration on which the implementation of HARQ feedback is based is the type 5.
The reference frame configuration on which HARQ feedback is based is shown in table 10.1.3.1-1 in 3GPP TS 36.213, and the following table 2 lists the table:
TABLE 2uplink anddownlinkframe con-subframefiguration01234567890——6—4——6—41——7, 64———7, 64—2——8, 7,————8, 7,——4, 64, 63——7, 6, 116, 55, 4—————4——12, 8,6, 5,——————7, 114, 75——13, 12, 9,———————8, 7, 5,4, 11, 66——775——77—
The meaning of the table is that, for seven kinds of uplink and downlink frame configurations respectively, it regulates the HARQ-ACK transmission of which downlink subframe is carried by which uplink subframe. Taking the type 5 as an example, No. 2 subframe is the only uplink subframe, the uplink subframe is responsible for carrying the HARQ feedback of the 13th, 12th, 9th, 8th, 7th, 5th, 4th, 11th and 6th downlink subframe counted backward from the uplink subframe. This kind of relation between the uplink subframe and the downlink subframe, the HARQ feedback of which this uplink subframe carries, can also be called as association, and the set of one or multiple downlink subframes associated with a certain uplink subframe is recorded as K: {k0, k1, . . . kM-1}.